Device for high-frequency signaling



Oct. 16, 1923.

M. LATQUR DEVICE'FQR HIGH FREQUENCY SIGNLLIHG I Filed July 17, 1920 AQMMUML Owl Jul 1 Patent Patented Oct. 16, 1923.

mmus ILATOU'R,

DEVICEFOR HIGH-FREQUENCY,siennmna PTA-TENT OFFICE.

or rams, FRANCE.

' Application filed July 17, 1920. Serial No. 897,140.

(GRANTED man THE rnovrsrou's or an new or MARCH s, 1921, 41 srar. L., 1313.

T0 all 'whom it may concern Be it known that l, MARIUS LAToUR, citizen of the Republic of France, residing at 79 Boulevard Haussmann, Paris, in the Republic of France, have invented certain new and useful Devices for High-FrequencySignaling, of which the following is a specification. I

The following foreign, applications have been filed.-France, dated October 26, 1916;, #503,076; Germany, dated July 9, 1920; England, dated July 10, 1920, Patent #148,955; Belgium, Patent #288,301, dated June 29,1920; Denmark, dated June 21, 1920; Holland, dated September 7, 1920; Italy, dated July 8, 1920; Poland, "dated August .7, 1920, and Sweden, dated June 28,

My invention relates to high frequency telephone systems with particular reference to such systemsin which a high frequency alternator is used as a source the current of off rectified high frequency current. -This high frequency current, before it has been rectified, is more suitable to be acted upon by any "voice actuated device than direct current would be. It is then rectified in order to be easily passed through the excit-I ing winding whose impedance to high frequency current may be high.

My invention is, for the purpose of -clearness, set down in the appended drawing, where:

IFi diagrammatically one embodiment of the invention.

Fig. 2 is a. modification inwhich meansare provided to amplify the exciting current. J r plified. If this phenomenon be exaggerated,

I Fig. 3 is a further embodiment of the invention. q

In the two figures of the drawings, in

which the same letters are employedto designate the same parts, 1, 2, are the terminals used for the purpose ofconneetion with the exciting current source (notlshown), 3, 5,

are two induction coils, 4, 6, are tgYVO condensers, 7 is" a transformer, 8 15 the exclting winding of the high'frequency alternator,

gure 1 is-a view showing more or less 9 is the rectifier, 10 is a microphone trans former, 11 is a voice actuated device.

In the embodiment shown on Fig. 1 the high frequency current from the source "(not shown) connected to terminalsl and 2 flows through a tuned circuit comprising condensers 4 and 6 and the iron core inductance coils. 3 and 5; these coils are provided with an additional winding which is part of a circuit comprising also a voice actuatedde vice 11 and a direct current source.

The yoice actuated device may, as has been shown, be connected with the circuit by means of a suitable transformer.

The high frequency current is then rectified by'means ofa vapor rectifier 9 connected according to a known disposition with the exciting winding of the high frequency alternator.

The effect of the voice currents in the additional winding of coils 3 and 5 is, as well known, to modify the tuning of the high fre quency circuit and consequently to vary the impedance of the high frequency circuit con net-ted across terminals 1 and 2. The result will thenbe that the telephone current will indirectly cause the-exciting current of the alternator to vary.

Coils 3 and 5 may be combined with the transformer by giving the winding of the latter a corresponding number of turns and by suitably devising the magnetic core. The

microphone may be protected against exaggerated high frequency currents, by provision of a choke coil or, still better, of a stopper circuit tuned to the frequency of the high frequency current.

It is to be said that the current, once rectified, maybe passed again around the magnetic core of the coils 3 and'5. The latter disposition is shown in Fig. 2. In this way, the effect obtained is to a large extent amit must be noted thata self exciting system isobtained, which is adapted to generate sustained' oscillations. I Q

The high frequency current brought to the terminals 1' and'2 may be that generated by the high frequency alternator itself. In this case, a. self-exciting system is obtained, the by suitablyl modifying the return coupling "action of t e rectified current on the current stability of which may be exactly regulated in coils 3 and 5. The two windings on each of these coils may be combined into one.

In the case of'the embodiment shown in Fig. 1, in order that current may Toe-gemerated into the antenna only during actual speech in the microphone and may fall to a negligible quantity during the silent intervals, there will be provided a. permanent inverse excitation of the alternator, adapted to balance the residual excitation caused by the current rectified during the silent intervals. This balancing excitation may beapplied, either to winding 8, or to' an additional winding.

The inverse permanent energization is shown iii-Fig. '3 by means of a circuit 20 comprising a direct current source and a winding controlling the energiz ation of the alternator in a manner to annul the effect produced by the rectified current which traverses the winding 8 when the telephone.

transmitter 11' is not actuated by speech.

I n order not to render the device too complicated, the same result could be obtained by feeding the exciting winding through a transformer, instead of inserting it directly in circuit 8, 9. This transformerwould be analogous to a microphone transformer.

A direct electromotive force working in series with the high frequency electromotive force may be provided, in order to balance the polarizing electromotive force of the rectifier.

When receiving signals .inodulated by means of such a device, it will be advantageous to supe'rimpose on the received cur-' rent a locally generated current of the same frequency and of a higher intensity. The

resulting intensity thus obtained will then oscillate between two values, the difi'erence between which will be superior to the intensity of the received current, both currents at times helping each other and at other times opposing each other. In fact, the intensity of signals would thus be increased in such a manner as to allow reception with receiving stations, by which the current of "method consisting in modulating the mean amplitude of a high frequency alternating current, in rectifying the thus modulated high frequenc current and in feeding the exciting circuit of the alternator with the thus modulated and rectified high frequency current. I

2.. A high frequency signaling system comprising, 'in combination, a high frequency alternator, a rectifier connected with the exciting winding of said high frequency alternator, a transformer the secondary winding of which is connected with said rectifier and exciting winding and the primary winding of which'is part of an oscillating circuit comprising iron core inductances, the said iron core inductances being provided with additional windings connected with a voice actuated device.

' In testimony whereof I aflix my signature.

MARIUS LAT'OUR. 

